Dental alignment holders for use in producing dental restorations are well known in the art. The prime function and purpose of such dental alignment holder is to produce dental restorations which conform to the functional bite of the patient. Such dental alignment holders are used in the preparation of inlays, crowns, bridges, and the like.
The customary technique followed in utilizing such dental alignment holders is to prepare two stone models of the patient's jaws and to mount such models on such dental alignment holders. The technique for preparing such stone models may be summarized as follows: a functional bite is chewed in by the dental patient to provide a static record of the dynamic action of the mastication movements of the jaws. This static record of the functional bite of the patient is obtained by the dentist by placing softened dental wax over the prepared teeth and the masticating action of the opposed teeth with respect to the prepared teeth are recorded in wax. From this impression a dynamic record of the functional movements of the opposed teeth is poured in stone and a static functional counter cast or dental functional cast is formed which contains all of the movements of mastication such as centric, working lateral, balancing lateral, protrusive, etc. An impression of the prepared teeth is also taken for making a dental working cast which may contain removable dies which represent the prepared tooth or teeth which are to receive the dental restorations.
One prior art device which is sold under the trademark "Verticulator" is generally shown and described in U.S. Pat. No. 3,059,336, dated Oct. 23, 1962, in the name of August W. Windish, and assigned to J. F. Jelenko & Co., Inc. This instrument has two cantilever arms, each of which is supported in a horizontal direction by a heavy metal block with the two blocks normally spaced from each other by coil springs and guiding pins. The stone models are mounted on the inner faces of the cantilever arms so that when the supporting blocks are pushed downwardly into engagement with their cooperating or mating surfaces the teeth on the stone models are brought into functional bite position. It will first be recognized that the broad flat surfaces of the mating blocks must be extremely carefully machined, otherwise any irregularities on the mating surfaces of the blocks will be magnified by the cantilever arms and transmitted to the dental restorations. Also, the vertical pins which engage in the two blocks to guide the same in a vertical direction must have very close tolerances with the mating holes in each block to prevent canting of the blocks and hence magnification of error in the stone models. Such close tolerances frequently give rise to binding when hand pressure is applied to the surface of the upper block to press it into engagement with the lower block. Also, as far as is presently known, such cantilever types of instruments are not adapted for application with both quadrant and full denture models. Thus it is customary in the dental field to have two such instruments,--one for use with quadrants and the other for use with full denture models.
Applicant is also familiar with the following U.S. patents:
______________________________________ Number Dated ______________________________________ 613,772 Nov. 8, 1898 1,027,443 May 28, 1912 1,033,562 July 23, 1912 1,684,393 Sep. 18, 1928 2,611,961 Sep. 30, 1952 3,067,515 Dec. 11, 1962 ______________________________________
None of these prior art patents discloses the salutary features of the present invention, nor do they disclose the universality of the instrument of the present invention.